<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<style>
    *{
        padding: 0;
        margin: 0;
    }
    .left{
        width: 200px;
        height: 200px;
        background-color: red;
        float: left;
    }
    .right{
        width: 200px;
        height: 200px;
        background-color: green;
        float: right;
    }
    .center{
        height: 300px;
        background-color: pink;
        overflow: hidden;
    }
</style>
</head>
<body>
<div class="left">left</div>
<div class="right">right</div>
<div class="center">center</div>

</body>
</html>
